Sunday, August 29, 2010

Sir Gilbert Blane



Sir Gilbert Blane was born on August 29, 1749, at Blanefield, Ayrshire, Scotland the fourth son of a merchant who he was named after. Little is known about his early life other than the fact that he attended school at Kirkoswald and Maybole. At the age of 14 he was accepted into the Faculty of Arts at Edinburgh University, with the intent of joining the church. Soon his course changed and he began studying medicine taking his M.D. from Glasgow University in 1778.

After graduating he traveled to London, where with letters of recommendation he began his medical career. He became the physician of Admiral (later Lord) George Rodney and traveled with Rodney to the West Indies in 1779. Blane soon became the Physician to the Fleet, being appointed over men who had more naval experience than he had. Blane saw action in six engagements and wrote an account of the Battle of Saintes. Upon his return to Britain, Blaine was awarded a pension from the Admiralty.

While he was with the fleet Blane published, at his own expense, his notes on naval hygiene including recommendations on improvements in hygiene and diet aboard naval vessels. One of Blane's recommendations was the inclusion of fruit into the diet of sailors, to prevent scurvy. At the time the British Navy was losing more men from infection and scurvy than it was losing as casualties of battle. Adhering to Blane's recommendations Rodney's fleet lost not a single man to disease or scurvy for a six month period, from December 1781 to May 1782.

Blane was not the first to discover that fresh fruit prevented scurvy in sailors. In 1747 James Lind, a naval surgeon, divided a group of twelve sailors with scurvy into six groups of two and gave each group a different treatment: the first group was given cider, the second dilute sulfuric acid, the third vinegar, the forth sea water, the fifth fresh oranges, the sixth a spicy paste and barley water. The treatment of group five stopped after six days when they ran out of fruit, but by that time one sailor had recovered and the other was on the way to recovery. In 1768-71 Captain James Cook circumnavigated the world and did not lose a single sailor to scurvy, a feat that was attributed to their stopping to replenish supplies of fruit throughout the voyage.

Blane returned to England at the end of the war in 1783 and established a practice being appointed to be physician at St. Thomas Hospital. In 1795 he was appointed commissioner of the Sick and Wounded Board of the Admiralty. As a commissioner he was able to push through the long needed addition of lemon juice to the provisions of British Naval vessels. Tough he did not discover the link between citrus fruit and scurvy prevention it was Blane who made sure that lemon juice was provided to sailors, an advance that provided the British Navy the man power it would need to fight the Napoleonic Wars. Blane married in 1786 and would have six sons and three daughters. He also served as the personal physician for the Prince of Wales, later King George IV. In 1812 he was sent to investigate the ill fateded Walcheren Expedition and for his service to the crown he was created a baronet.

Blane died in his home in Sackville Street, London on June 26, 1834.


References:


Leach, R. H.; Sir Gilbert Blane, Bart, MD FRS (1749-1832); Annals Royal College of Surgeons (1980)62:232-239

Wharton, Mary; Sir Gilbert Blane Bt (1749-1834); Annals Royal College of Surgeons (1984)66:375-376

Sunday, August 22, 2010

Denis Papin



Denis Papin was born in Blois, France on August 22, 1647, the son of a royal official. Although his family was Cavinist he attended a Jesuit school in Blois and in 1661 went to the University of Angers where he graduated with a medical degree in 1669. He practiced medicine for two years, until he accepted the offer of Christiaan Huygens to come and work as his assistant. The position was a combined research assistant/curator post at the newly established French Academy. He published several papers jointly with Huygens detailing their experiments with an air pump, and he published a book detailing his experiments to determine the weight of atmospheric air in 1674.


The following year Papin went to London, probably because of his Protestantism, which made his life in France difficult. In London he obtained a similar position to the one he had in France at the Royal Academy, with the assistance of Robert Boyle, who had read his book. At the Royal Academy he continued his experiments on atmospheric weight and did experiments with steam. During his tenure at the Royal Academy he invented a pressure cooker that extracted nutrients from bones and other things not normally digestible by humans. This was probably the most profitable invention of his but he gained little in the way of payment for it. One interesting feature of this invention was a valve by which excess steam could be let off, similar to valves used in later steam engines to prevent dangerous over pressurization.


In 1681 he went to Venice, but returned to London three years later. Later he was invited to take the chair in mathematics at the University of Marburg, where he married his cousin who was a widow with a daughter. The remittance for this position was less than what he required for his new family. In 1696 he moved to Cassel there he was able to complete experimental designs including a centrifugal pump, a diving bell and a submarine boat. He also concieved of ways that mechanical power could be transported over a distance by means of a vacuum tube. He received requests from mine owners for assistance in removing water and ore from their mines. Although he cannot be credited with the invention of the steam engine, his researches were pivitol in its development. He remained in Cassel until 1707 when he returned to London, leaving his family in Germany. He presented a few papers to the Royal Academy, but he was largely destitute.


The last surviving evidence of his existence is a letter dated January 27, 1712. It is believed that he died thereafter and was interred in a paupers pit grave.


References:

Ewart, Henry C.; "Denis Papin: A Life's Work and it's Moral"; The Sunday Magazine(1880)9:316-319

Matschooss, Conrad; Great Engineers; Ayer Publishing, 1970


Denis Papin Wikipedia Entry

Sunday, August 15, 2010

Prince Louis-Victor de Broglie


Prince Louis-Victor de Broglie was born in Dieppe, France on August 15, 1892., the younger son of Victor Duc de Broglie and Pauline d'Armaille. The history of the de Broglie family included service to the French crown for which the head of the family was granted the hereditary title of "Duc" (Duke) by Louis XIV and the German title of "Prinz" (Prince) for service to Austria during the Seven Years War. All of de Broglie's early education was provided by private tutors. In 1906 he was sent to Lycee Janson de Sailly where he spent three years completing his secondary education. De Broglie then went to the Sorbonne where he initially studied history, intending to take a job in the diplomatic service, earning a degree in 1910. Unsatisfied with his studies in the liberal arts de Broglie began studying theoretical physics.

De Broglie graduated with a degree in physics in 1913. Thereafter, as required by French law, de Broglie enlisted in the military. De Broglie served for the duration of the First World War, from 1913 to 1919. In his initial posting he was sent to a fort at Mount Valerien, where he was given very little to do and it was a difficult time for him. Later, with the influence of his brother Maurice, who had succeeded his father as Duc, de Broglie was posted to a radio station at the Eiffel Tower working as an electrician. De Broglie found this posting much more satisfying as it allowed him experience working with electrical equipment, which would serve him well in his scientific career.

After leaving the French service de Broglie worked with his brother Maurice, also a theoretical physicist, taking advantage of the laboratory built by his bother at the family mansion in Paris. At the time physicists thought of matter as being composed of particles and light was thought of as a wave-like phenomena. Albert Einstein, in his description of the photo-electric effect had demonstrated that light can behave both as a particle and a wave. Influenced by Einstein, de Broglie proposed that matter also has a dual nature, as both a particle and a wave. He proposed that the wavelength of matter is equal to Planck's constant divided by the momentum of the particle (wavelength h/p). This is true for all matter, small particles like electrons and large objects such as bullets or cars. Because of the momentum term in the wavelength equation (p) is equal to the mass of an object multiplied by its velocity (p=m*v) the wavelength gets shorter the more massive an object is and it is only for small particles that the wavelength has any practical effect. Using this insight for his doctoral thesis, his committee was unsure of the validity of his ideas and so passed his thesis on to Einstein who wholeheartedly agreed with the work. De Broglie was granted his doctorate in 1923.

De Brolie's insight into the wave nature of matter gave rise to a field of physics called wave mechanics. An electron, traveling around a nucleus, must have a wave pattern that is stable, where the length of the orbital is an integer number of wavelengths long. Erwin Schrodinger used de Broglie's theory of particle waves to work out the solutions to the wave equation that showed the behavior of an electron in a hydrogen atom and these equations agreed with experimental data.

For his discovery of the wave nature of matter de Broglie was awarded the Nobel Prize in physics in 1929. After completing his doctorate de Broglie gave a series of lectures at the Sorbonne, and was appointed professor of theoretical physics at the Poincare Institute in 1926. In 1932 he was appointed chair of theoretical physics at the Sorbonne where he taught until 1962.

De Broglie died on March 19, 1987.


References:

"Biography of Prince Louis-Victor de Broglie the Nobel Prize in Physics 1929" at debroglie.poldow.com

Prince Luis de Broglie Nobel Biography

Luis de Broglie Wikipedia Entry

Sunday, August 8, 2010

Ernest Orlando Lawrence


Ernest Orlando Lawrence was born in Canton, South Dakota on August 8, 1901, the son of Carl Gustavus and Gunda Lawrence. His parents were Norwegian immigrants and his father was superintendent of schools. He attended Canton High School and then St. Olaf College in Northfield, Minnesota. In 1919 he went to the University of South Dakota, working his way through college by selling kitchenware. Originally he studied for a medical career but switched to physics. He graduated in 1922 with a B.A. in Chemistry. He then went to the University of Minnesota where he earned an M.A. in physics in 1923. He then went to Yale finishing his Ph.D. in physics in 1925 completing a thesis on photoelectricity.

He remained at Yale for three more years as a National Research Fellow and assistant professor. In 1928 he left the relative comfort of his Yale position as an assistant professor to become an associate professor at the University of California Berkley. Two years later he became a full professor at Berkley, being the youngest professor at Berkley. In 1936 became director of the university's radiation laboratory. He remained at these positions until his death.

Lawrence's early research dealt with photoelectricity and the ionization potentials of gaseous metals. In 1929 he invented the cyclotron, a device which accelerates atomic particles without using high voltages. Cyclotrons use an alternating voltage to accelerate particles, and a perpendicular magnetic field holds the particles in a circular path so that they can re-encounter the accelerating voltage many times. Thus the particles are gradually sped up by multiple encounters with the accelerating voltage. Cyclotrons, because the accelerated particles move in a circular path, take up less space than linear accelerators. Cyclotrons are used to create non-naturally occurring elements by bombarding atoms with atomic particles to create larger atoms. Cyclotrons have also been used in medicine to bombard cancerous tumors with radioactive particles.

During World War II Lawrence worked to help develop the atomic bomb. His radiation laboratory actively took part in the research for the development of the bomb. A early proponent of electromagnetic separation of uranium isotopes he developed calutrons, a specialized type of mass spectrometer, to separate the isotopes. He also introduced J. Robert Oppenheimer into what would become the Manhattan Project.

In 1939 Lawrence won the Nobel Prize "for the invention and development of the cyclotron and the results obtained with it especially with regard to artificial radioactive elements." Other honors received by Lawrence include the Enrico Fermi Prize awarded by the U.S. Atomic Energy Commission in 1957 and the Sylvanus Thayer Award presented by the United States Military Academy. Element 103 (atomic number 103) is named Lawrencium after Lawrence.

In 1958 Lawrence was appointed by President Eisenhower to take part in the negotiations with the Soviet Union over and atomic weapons treaty. Despite suffering from colitis Lawrence decided to go to Geneva, to take part in the negotiations. Falling ill while he was in Geneva Lawrence was rushed back to America for medical treatment. Lawrence died one month later on August 27, 1958.


References:

Alvarez, Luis, "Ernest Orlando Lawrence"; in Biographical Memoirs (1970) National Academy Press


Ernest Lawrence Nobel Prize Biography

Ernest Lawrence Wikipedia Entry

Sunday, August 1, 2010

Georg Charles de Hevesy


Georg Charles de Hevesy was born on August 1, 1885 in Budapest, Hungary. He was the fifth of eight children of Louis de Hevesy, a public prosecutor and Eugenie (Schossberger) de Hevesy. Beginning in 1903 he attended Budapest University and Berlin Technical University studying chemistry, physics, and mathematics. He earned his doctorate in chemistry at the University of Freiburg im Breisgau in 1908.

He worked for two years at the Institute of Physical Chemistry, Technical University of Switzerland before working for a short spell with Fritz Haber and seeing much of the fundamental work Haber did developing the Haber process to synthesize ammonia. He traveled to Manchester, England in 1910 to study under Ernest Rutherford. Rutherford gave him the task or separating out the radium D from the large amount of lead in a sample of Joachimsthal pitchblende which had been given as a gift by the Austrian government. Of course, try as he might de Hevesy was not able to complete the separation. He was able to use radium D and radium E as a radioactive tracer in investigations of the kinetics of lead and bismuth in plants.

Radium is the heaviest of the alkaline earth metals (group 2 on the periodic table) and is intensely radioactive. The products of radium's decay have been historically known as A, B, C etc. Radium D is now known as lead-210, so of course de Hevesesy was unable to separate the radioactive lead isotope from the non-radioactive lead by normal chemical means, but he was able to use it as a radioactive tracer. Other experiments he performed using radioactive isotopes as tracers included using duterated water (water with radioactive hydrogen) as a tracer to determine the amount of water in the human body and using radioactive phosphorus to determine the rate of deoxyribose nucleic acids in liver and kidney cells. He also was able to determine the lifespan of red blood cells and the doubling time of artificially induced tumors using radioactive tracers.

In 1919 de Hevesy went to work at the Bohr Institute for Theoretical Physics in Copenhagen (he had become friends with Niels Bohr while working in Manchester). Bohr had de Hevesy investigated samples of zircon ore for element number 72, then an empty space on the periodic table. Working with Dirk Coster, he was able to find the missing element and named it hafnium, after the Latin name for Copenhagen, Hafnia.

In 1940, when Germany invaded Denmark, de Hevesy dissolved the Nobel Prizes of Max von Laue and James Franck in aqua regia, to prevent the Germans from stealing them, and placed the solution on a shelf in the Bohr institute. Afterwards he was forced to flee Denmark to Sweden, because of his Jewish ancestry. After the war he returned to find the solution still on the shelf where he had left it and precipitated the gold out. He gave the gold to the Nobel Society, which recast the prizes. In 1943 de Hevesy was awarded the Nobel Prize "for his work on the use of isotopes as tracers in the study of chemical processes".

De Hevesy died on July 5, 1966.


References:

Feld, Michael, de Roo, M.;History of Nuclear Medicine in Europe; Schattauer Verlag; 2006

George de Hevesy Nobel Biography

Geroge de Hevesy Wikipedia Entry